Most of the suspects have not yet been identified by name, but have been singled out in picture or video recordings.
The total number of crime reports submitted to police in the western cathedral city reached 121 by Thursday, with around three-quarters of them relating to sexual assault.
Two women submitted reports of rape.
Germany has been shocked at the extent of the thefts, violence and sexual assaults on New Year's Eve in Cologne – and at the apparent inability of police to handle them – vivdly depicted in a police report that emerged on Thursday.
The perpetrators were among a large crowd of men of reportedly Arab or north African backgrounds who gathered around the train station, drinking and discharging fireworks.
Politicians and police have been pointing the finger of blame at one another – while the racially charged character of the events has poured fuel on the fire of an already tense debate over the number of refugees in Germany.
While there is no evidence that any of the perpetrators were refugees, conservatives and the far-right have gladly built the attacks into complaints over the large numbers of Muslims who have arrived in Germany seeking asylum since summer 2015.
'Self-defence force' forms in Düsseldorf
Meanwhile, a number of people in Düsseldorf – one of Cologne's neighbouring cities – joined a group urging the formation of a "Bürgerwehr" or self-defence force on Facebook, the Rheinische Post (RP) reported on Thursday.
Organizers in the group posted that they planned to "patrol through the city" to help women if they saw them under attack.
They said that the group was not political or violent, but had simply formed to make the city "safer for our women".
Around 1,000 people had joined the group, which plans its first outing on Saturday, after it had existed for just one day.
"The police are responsible for public security in Germany," a city police spokesman told RP. "Going in search of criminals in a conscientious and targeted way is not the business of ordinary citizens."
SEE ALSO: Police report shows their side of Cologne assaults